Concrete-pipe machine.



1. e. ZWICKER CONCRETE PIPE MACHINE. APPLICATION FILED IUNE13, I9I6- Patented Aug. 13, 1918.

5 SHEETS-SHEET l.

1 JD. 85 A57 s. 55v WITNESS g9 97 96 INVENTOR.

I v (W4 1' K 37 3 ,Z r a ATTORNEY.

J. G. ZWICKER.

CONCRETE PIPE MACHINE. APPLICATION FILED JUNE 13. I916.

Patented Aug. 13, 1918.

5 $HEETSSHEET 2- INVENTOR. 4 Z/rfczfipg WITNESS A TTORNE Y.

J. G. ZWICKER. CONCRE TE'PIPE MACHINE.

APPLICATION FILED JUNE 13. I916- 1,275,853,

Patented Aug. 13,1918.

1 .5 SHEETSSHEET 3.

I I I A TTORNE Y.

J. G. ZWICKERQ CONCRETE PIPE MACHINE.

' APPLICATION FILED JUNE 13, l9i6. H 1,? 358 Patented Aug. 13, 191.8.

5 SHEETS-SHEET 4.

WITNESS 7 9 IN VENTOR: -2% fad-W ZMZIVM A TTORNE Y.

J. G. ZWICKER. CONCRETE PIPE MACHINE. APPLICATION FILED JUNE I3. l9I6- 4 I Patented Aug. 13, 1918.

5 SHEETSSHEET 5.

INVENTOR. %a-M Z Mm W 1 TNESS A TTORNE Y.

JULIUS G. ZWICKER, OF BERKELEY, CALIFORNIA.

CONCRETE-PIPE MACHINE.

Specification of Letters Patent.

Patented Aug. 13, 1918.

Application filed June 13, 1916. Serial No. 103,394.

To all whom it may concern:

Be it known that I, JULIUS G. ZWICKER, a citizen of the United States, residing at Berkeley, in the county of Alameda and State of California, have invented certain new and useful Improvements in Concrete- Pipe Machines, of which the following is a specification. Y

My invention relates to an apparatus for molding tubular pipe sections, and is particularly adapted to the use of concrete as the molded material.

In the manufacture of molded concrete pipe, it is highly desirable to use a comparatively wet mixture, especially when reinforcing is employed. Such a mixture can be'economically handled, as by being led through ducts or pipes, and poured into the molds, and, what is of still greater importance, it readily flows into all the spaces of the mold, and completely and closely surrounds the reinforcements.

The principal objection to the use of wet or poured concrete for this purpose has heretofore been the length of time required for such concrete to set and harden sufficiently to enable the article to be removed from the mold, said time usually amounting to a number of days. In the manufacture of such articles as concrete pipe sections, which are made in great numbers, this delay in setting necessitates the provision of a great number of molds, and results in an unduly large financial outlay for the molds, which must have a high degree of accuracy, and are necessarily costly to manufacture.

et or poured concrete can, however, be artificially preliminarily compacted by pressure; that is, the excess or surplus water content can be squeezed out, and by so doing, the concrete is rendered sutlicientl} hard to enable the mold to be removed at"- once. The advantages accruing from the use of a wet mixture can by this means be retained, and at the same time the disadvantage of a long setting period may be obviated.

Moreover, the use of pressure, especially when applied as is contemplated by my invention, namely in a direction at right anglesto the axis of the molds. that is, to the side of the section to be molded, makes a more compact and homogenous mass, and gives adegree of accuracy to the molded sections which can not be otherwise obtained, and thus the finished product made by my invention is better and more solid than the ordinary naturally set product.

The objects of my invention are two-fold; first to provide a molding apparatus by means of which a wet or poured concrete mixture may be artificially and rapidly set, to enable its immediate removal from the mold; and secondly to provide, in such an apparatus, a mold of absolute accuracy, whereby every article molded therein will be identical in all respects with every other article. This latter feature is of considerable importance in the manufacture of concrete pipe sections having threaded end portions for mutual engagement, for the suecess of such pipe, and its ability to withstand interior pressure, depends very largely upon the accuracy of the screw joints, not only in the threads themselves but also the abutments of the ends.

' By the employment of the apparatus, embodying the present invention, I am enabled to make concrete pipe sections with threaded end portions, of absolute and unvarying accuracy, so that when said sect-ions are united together, by means of said threads, into a continuous pipe, said pipe will stand a pressure of several hundred pounds 'without leaking; and on account of their accuracy, the joints are able to withstand any pressure up to that required to burst the pipe. Such pipe is easy to handle and install, and is perfectly capable of withstanding the pressures usually required of water, gas, or oil mains; and in addition, it is not subject to corrosion, electrolytic or otherwise, or to deterioration of any kind, so that its permanence is therefore absolute.

By the use of my machine, moreover, I am enabled to make a complete section or pipe and remove it from the mold in approximately three minutes. The ring moldsfor forming the threads upon the ends of the pipe are allowed to remain upon the pipe for twenty-four hours, said thread molds being substantially the same as those for which United States Letters Patent No; 1,181,198 were isued on May 2, 1916, to Julia Powell Zwicker, under title of apparatus for making threaded concrete-pipe. Thus by the use of one machine and a number of thread molds, I am enabled to make a great many pipe sections in a comparatively short time, and at comparatively little cost.

The preferred form of the apparatus hereinafter described and herewith illustrated is particularly adapted for making pipe sections of concrete.

It is to be understood, however, that the- With this in view, reference should be had to the accompanying sheets of drawings, wherein-- Figure 1 is an elevation, on a greatly reduced scale, of the entire apparatus.

Fig. 2 is a plan view of the same, showing the arrangement of the operating handles.

Fig. 3 is a part-sectional elevation, enlarged from Fig. 1,.of the upper end portion of the machine.

Fig. 4 is a detailed plan of a portion of the top of the machine.

Fig. 5 is a detailed horizontal section taken in the direction of the arrows on the line 5-5 of Fig. 3.

Fig. 6 is a part-sectional plan view, enlarged, taken in the direction of the arrows on the line 66 of Fig. 1, certain 'parts being broken away for the sake of clearness.

Fig. 7 is a part-sectional elevation, enlarged, of the central and lower portions of the mold or press mechanism, taken in the direction of the arrows on the line 7-7 of Fig. 6.

Fig. 8 is a plan view taken in the direction of the arrows on the line 8-8 of Fig. 7.

Fig. 9 is a horizontal section, enlarged, of the inner mold, or core.

Fig. 10 is a detailed vertical section, enlarged, of the upper end of the core or inner mold.

Fig. 11 is a plan-detail of a portion of one of the thread molds and the frame, showing their interlocking relation.

Fig. 12 is a vertical section of the same,

taken on the line 12-12 of Fig. 11.

Fig. 13 is a art sectional view similar to Fig. 11, showing the means for correctly locating the thread mold.

Referring now in more detail to the drawings, the frame of the machine is composed of four. vertically disposed angle members, designatedby the reference numeral 1, and spaced as shown in Figs. 1 and 6. These angle members 1 extend both above and below the floor 2, Fig.1, and are secured thereto by a suitable base member 3. Between each adjacent pair of angle members 1 is a longitudinally disposed screen section 4, forming aportion of a cylinder. As there are four of these-screen sections 4, disposed as shown in Fig. 6, they form a complete screen is preferably of a type well known in many arts and-devices, such, for example, in grain milling and pearl'ing machines, that is, sheet metal, perforated at frequent intervals by very narrow slits. I have, however, in the drawings, indicated this screen merely conventionally.

In its present use, the selection is made of such a screen the width of whose slits is such that when pressure is applied, water will be forced therethrough, but the solid portions of the pressed concrete will be held within.

Each of these outer mold screen-sections 4 is mounted for limited lateral movement between its bounding frame members 1, so

that, by the simultaneous movement of all' ciated therewith the mechanism which will now be described in detail, it being under stood that there are four identical sets of said mechanism, one associated with each mold section 4.

Each mold section 4 has secured thereto and extending rearwardly or outwardly therefrom a number of horizontal thrust plates 5, Figs. 6 and 7, said plates having a free sliding fit between the angle members 1, and acting as guides for said mold section 4.

Behind said thrust plates 5, and bearing equally against all of them, is a vertically disposed follower 6, preferably of channel section. A pair of interiorly threaded sockets 7 are fastened to the back of said follower 6, from which project screw pins 8, the latter being supported by and having journals within yoke brackets 9 secured to the angle members 1. Upon the outer ends of said screw pins 8 are mounted bevel gears 10, meshing with teeth 11 'cut upon the upper and lower faces of aring 12, said ring encircling the four frame members 1 and being supported and guided by suitable bearing brackets 13 projecting therefrom.

At one side of the machine is a bracket 14, Fig. 6, fixed to one of the frame members 1 and extending therefrom radially with respect to the gear ring 12. A short shaft 15, rotatably mounted within said bracket 14, carries -a bevel pinion 16, adapted to mesh with an outer series of teeth 17 formed upon the gear ring 12. The outer end 18 of said shaft 15 is adapted to receive some form of driving means, as, for example hand wheel 19, as shown in Fig. 1. Thus it will be seen, thatby means of the hand wheel 19, the gear ring 12 may be rotated, and this motion, through the agency of the bevel gears 10 and the screws 8, will cause all four outer-mold screen sections 4 to be moved in or out simultaneously, to contract or expand the cylinder formed thereby. To cause said mold sections 4 to move out with the followers 6 in their outward movement, one or more of the thrust plates 5 is provided with arms 5 extending on each side of said follower 6, and carrying a tie bar 6 behind said follower, as seen in Fig. 6.

To provide additional support for the mold section 4 between the thrust plates 5, the material of said mold section is bent back to form flanges 20, Fig.6, and back plates 21 are placed across said flanges, said plates 21 having longitudinal ribs 22 adapted to bear against the follower 6. It should be clearly understood that the flanges 20 and the back plates 21 extend only between the horizontal thrust plates 5, the latter transmitting the major portion of the thrust from the follower 6 to the mold section 4. Said back plates 21 are readily removable, to permit of cleaning the outer surface of the perforated mold section 4. The thrust plates 5 are formed with drainage apertures 23, as shown.

Within the outer mold formed as above described is a core carrying the mold for the inner surface of the pipe section, said inner mold being concentric with the outer mold and 'of approximately the same length. Said inner mold is formed of perforated or screen material similar to that used in the outer mold, and is divided longitudinally into a number of sections 24, preferably four in number, as shown in Figs. 6 and 9 of the drawings, and constituting, when assembled, a substantially cylindrical structure.

The core or inner mold is supported by an axially disposed hollow rod or tube 25, Figs. 3, 6, 7, and 9, to which are fastened a bottom end plate 26, Fig. 7, and a top end plate 27, Fig. 3. Between these end plates 26 and 27 extend four triangular spacer rods 28, one between each pair of adjacent mold sections 24. The central supporting tube 25 is surrounded, between said end plates 26 and 27, by a rotatable sleeve 29, which carries a plurality of sets of eccentrics 30, there being four eccentrics in each set, placed 90 degrees apart, one for each mold'section 24. Each eccentric 30 is surrounded by a strap in the form of a flat horizontally disposed plate 31, which'extends outwardly to one of the mold sections 24, and. lies below and adjacent to a locking plate 32, the latter being fixed to the said mold section 24' and extending inwardly therefrom to partially embrace the eccenas shown at 34, to provide drainage apertures.

Thus it will be readily understood that a partial rotation of the sleeve 29, carrying the eccentrics 30, will cause, through the agency of the eccentric strap plates 31 and the locking plates 32, all four mold sections 24 to move simultaneously in or out, to contract or expand the cylinder forming the inner mold surface. For the purpose of causing such partial rotation of the sleeve 29, a collar 35, Figs. 3 and 5, is provided upon the upper end of said sleeve, immedi-. ately below the upper core end-plate 27, and said collar 3-5 is formed with a lateral socket 36 into which a bar, not shown in the drawings, may be inserted. The partial rotation of said sleeve caused by the manipulation of said bar is sufficient to move the mold sections 24 the desired distance.

At the ends of the annular cylindrical mold formed by the outer and inner concentric surfaces 4 and 24 respectively, are. the thread molds for forming the connecting screw-threads on the ends of the pipe sections, said thread molds being preferably, as before stated, substantially of the form for which United States Letters Patent No. 1,181,198 were issued to Julia Powell Zwicker on May 2, 1916, and forming no part of the present invention, except in so far as they are adapted to the present machine as will'be fully described.

Slightly below the lower ends of the outer mold sections is a ring 37, Figs. 7 and 8, 1 ing within theangle frame members 1 and xed thereto, as by means of. screws 38. Said ring is preferably formed with annular corrugations 39 on its upper surface, and with a pair of oppositely disposed grooves 40, the latter being for a purposeto be set forth hereinafter.

Upon this ring 37, as seen in Fig. 7, rests the bottom or female thread mold 41 The interior diameter of said thread mold 41 is such as to make a close fit about the. lower end of the inner core when the latter is expanded, as shown in Fig. 7. The flange 42 of said mold 41 is peripherally shouldered, at 43, and is of 'a diameter to fit within the outer mold cylinder 4, when said outer cylinder is expanded, this construction permitting the thread mold to be lowered into position through said outer cylinder. The peripheral shoulder 43 of thevv flange of said thread mold is notched in four equally &

spaced positions, to fit over the inner corners of the four frame members 1, one of said notches being wider than the others, and a shim is fixed to one of said frame corners, in a manner to be later described in connection with the top thread mold, to insure the correct positioning of the thread mold.

The thread mold 41 is retained in position by four horizontally disposed sliding plates 44, Figs. 6 and 7, one between each adjacent pair of frame members 1. Said plates are supported at their inner ends by rollers 45, and at their outer ends by a rotatable ring 46 surrounding the entire frame, and supported by suitable brackets 47 projecting therefrom. Said ring 46 'is provided with four substantially tangential or eccentric cam slots 48, into which project pins 49 fixed to said plates 44. Alever mechanism, indicated at 50 in Figs. 2 and 7, is provided for imparting to said ring 46 a partial rotative movement, said movement being sufiicient to cause the plates 44 to move simultaneously in or out to engage or release the peripheral shoulder 43 of the thread mold 41.

The top or male thread mold 51, Fig. 3, lies within the frame members 1 immediately above the upper end of the outer mold cylinder 4, which is not earned up as far as the inner mold or core 24. ThlS top thread mold is flanged, at 52, and the lower portion of said flange is notched in four places, as at 53, in Figs. 3, 11 and 1,2, to fit over the corners of the four frame members 1. Said frame corners are cut out, as at 54 to receive the continuous upper portion of the fiange 52, the shoulder 55 forming a support for the thread mold. One of the notches 53 is wider than the others, as shown at 53' in Fig. 13, and a shine 56 1s affixed to one of said frame corners, to permit the thread mold 51 to be placed in one position only. The bottom thread mold 41 is correctly located by a smiliar construction, as previously referred to.

The top thread mold 51 has an inwardly extending top flange 51 which bears closely against the inner mold 24, so that the top of said thread mold is closed. Said thread mold is firmly clamped by four horizontally disposed slidable plates 57, Figs. 3 and 4, one between each adjacent pair of frame members 1 The inner ends of said plates 57 are supported upon rollers 58, and are areuate, to closely abut against the periphery of the thread mold. The outer ends of said plates rest upon a rotatable ring 59, said ring surrounding the entire frame, and being supported by suitable brackets 60. Ec-

centric or substantially tangential cam slots 61 in said ring 59 are engaged by pins 62 fixed to said plates 57, so that by a partial rotation of said ring, all of said plates 57 may be simultaneously moved in or out, to clamp or release the thread mold 51. Suitable handles 63 are provided upon said ring 59 for turning the same, and an adjustable stop 59 is mounted upon said ring, to limit its movement by contact with the frame member 1.

The top thread mold 51 is retained in position, by cover plates 64 and 65, hinged respectively at 66 and 67 to fixed brackets 68 and 69to swing upwardly and outwardly in opposite directions. The adjacent inner ends of said plates are cut out in semi-circular form, to closely embrace the upper end portion of the inner mold or core 24, and are provided with semi-circular ribs 70 on their under surfaces, adapted to bear against the thread mold 51. The plate 64 carries a dog 71, which engages a socket 72 in the upper end plate 27 of the core, to correctly and positively locate said core, and to prevent the rotation thereof. Said cover plate 64 also carries two projecting arms 73, spaced to straddle the core end plate 27, and extended to overlie the plate 65. A swinging bracket 74 is provided, carrying a rotatable cross shaft 75 upon whose ends are eccentrics 76, adapted to engage and clamp the ends of the arms 73 upon the underlying plate 65, thus forming a secure lock for both cover plates 64 and 65. A handle 77 is provided, to operate the locking eccentric shaft 75.

Below the mold portion of the machine is a drip can 78, Figs. 1 and 7, set within the frame members 1 and extending from a point slightly below the bottom thread mold support 37 downwardly to the lower ends of said frame members. Close fitting plates 7 9', Fig. 7, are positioned between each pair of adjacent frame members, to catch the water squeezed out of the concrete during the pressing thereof, and to direct said water into the drip can 78. Said can is provided with a suitable drain or draw-ofl' valve, not shown in the drawings.

The central core-supporting tube 25 is adapted for vertical movement, to lower the core out of the mold into the drip can 78. F or-this purpose said tube 25 is extended downwardly through a packing gland 80, Fig. 1, in the bottom of said drip can, and through a bracket 81supported by a hanger 82 depending from one of the frame memwheel 88 within easy reach of the operator of the machine. I

For the purpose of washing the core surface 24, a ring of perforated tubing is posi-' tioned, horizontally, immediately-below 'the bottom thread-mold support 37, as shown at 89, in Figs. 7 and 8. Said ring is supplied with water by means of a pipe 90, Fig. 1, in which is a shut-off valve 91, operated by means of a lever 92. The lever 92 carries on its end a cam follower 93 whichrides around the edge of a cam bar 94 carried by a bracket 95 fixed to the movable'tube 25, in such a manner that on the upward movement of said cam bar 94, the valve 91 is held in closed position, and on the downward movement of said bar, said valve is held open. This allows water to flow to the spray ring 89, and issuing therefrom in inwardly directed jets, washes the core surface 24 as the same descends out of the mold.

Similar means are provided for washing the outer mold surface 4. Water is admitted, througha flexible connection 96, Fig. 1, to the lower end of the central tube 25, and is controlled by a shut-off valve 97, said valve being operated by a lever 98 whose end follows a' cam 99 upon the lower portion of the fixed hanger 82 in such manner that said valve is held open only during the upward stroke of the tube 25. Thus during 'said upward stroke, water is admitted to said tube 25, and, issuing as a spray from a series of holes 100, Fig. 3, near the upper end thereof, washes the outer mold surface 4 as said upper end portion of the tube 25 passes upwardly therethrough.

When the core is in place within the outer mold, the central core supporting tube 25 extends somewhat above the top of the mold, as shown in Fig. 3. Upon this upper end portion of the tube 25 is a close-fitting, but freely slidable plunger 101, whose greatest exterior diameter is slightly less than the interior diameter of the molded pipe section.

A removable pin102 is provided to support said plunger, and a freely sliding weight 103 rests upon said plunger, to force the same downward, when said pin is removed, for a purpose to be set forth hereinafter, in connection with the description of the operation of the machine.

The top of the central core supporting tube 25 is closed, by an upwardly projecting dowel pin 104, Fig. 3, which is adapted to receive and support a removable gripper device, comprising a central rod or tube 105, the lower end of which is hollow to fit over said pin 104, and the up er end of which is formed into a hook 106, y which the entire gripper device may be suspended. This central rod 105 is somewhat longer than the mold, so that its upper end projects above said mold when the tube 25 is in its lowest A sleeve 107 surrounds said rod position.

slidable relation, and is nor- 105 in freely mally supported by a removable pin 108 near its upper end. Said sleeve carries, at its of the pipe to be molded. The outer mold lower end, one or more pairs of dogs 109, pivotally connected at 110 with a bracket 111 fixed to said sleeve. A spreader 112 is carried by the rod 105 below said sleeve 107, so that when the pin 108 is removed and said sleeve 107 allowed to drop relative to rod 105, said spreader causesthe dogs 109 to swing" outwardly until the upper inclined surfaces 113 thereof lie against said sleeve, and the lower notch surfaces 114 assume a horizontal position. In this position, said dogs project sufliciently to engage the lower surface of the bottom thread mold 41 when the central tube 25 and the core have been lowered to their lowermost position, the grooves 40, Fig. 8, being provided in the ring 37 to permit such engagement.

The operation of the machine may be described as follows Assuming that the core or inner mold is is its elevated position, that is in the position shown inthe drawings, and that the cover plates "64 and 65 are open, the bottom thread mold 41 is lowered into place, and locked by the lever 50, which operates the ring 46 and the sliding plates 44, as shown in Fig. 7. The core sections 24 are then expanded, by a partial rotation of the sleeve 29, to make said core the correct diameter for the inside sections 4 are also in their fully expanded position, and the upper thread mold is not yet in place.

The mold is now ready for pouring. If any reinforcement is to be used, it is inserted into the mold at this time, previous to the in 'troduction of the concrete. Said reinforce? ment may beof any desired form, as, for example, a cylindrical cage having a plurality of longitudinal members tied together by rings or a continuous spiral. The concrete is then poured in through the open top of the mold, said concrete being sufliciently. fluid to fill all the spaces of said mold, and to flow completely around the reinforcement. The mold is thus filled to the top of the outer mold sections 4. v j

The top thread mold 51, Fig. 3, is next placed in position, and clamped by means of the ring 59 and its associated sliding plates 1 5 57, andthe inwardly extending top flange 51' of said thread mold closes the top of the molding space. The cover plates 64 and 65 are closed and locked by the eccentric clamps 7 6. The outer mold surfaces 4 are then con- 1 forations in the inner and outer mold surfaces, thus leaving the molded pipe section in a comparatively dry and exceedingly compact condition.

The core or inner mold can now be contracted, by the described mechanism, to free its surface from the inner surface of the molded pipe section. The cover plates 6-1 and 65 are opened, and the entire core, carried by the central tube 25, is lowered, by means of the mechanism operated by the hand wheel 88, Fig. 1,'until the upper end plate 27 of said core occupies a position slightly below the upper end of the molded pipe section, which said section is still held by the outer mold and the end molds. The space within said pipe section above said core end plate 27 is then filled with a quantity of rich plastic cement material, and the plunger 101 lowered thereonto, by the removal of the pin 102.

The core is now further lowered through and out of the molded pipe section, and the plunger 101, impelled by its weight 103, forces the plastic cement, contained between itself and the core end plate 27, out against the inner surface of the molded pipe, forming thereon a thin smooth coating, which, when dry, provides a smooth, hard, and close grained lining for said pipe.

During this downward travel of the core, the water valve 91, Fig. 1, is held open by the described mechanism, and the surface of the core is washed by the water jets issuing from the perforated ring 89, Fig. 7

This downward movement of the core is continued until the gripper dogs 109, Fig. 3, are below the bottom thread mold 41, whereupon the pin 108 is withdrawn, allowing the sleeve 107 to drop down. The dogs 109, riding out upon the spreader 112, assume.

their extended positions, the surfaces 114 being substantially horizontal and in position to engage the bottom surface of said thread mold 41. upper and lower, are released from their clamped association in the mold structure and the outer mold 4 is also expanded, thereby completely freeing the molded pipe section though the thread molds are still upon it.

The core or inner mold is thereupon raised to its initial position within the outer mold 4, and by the engagement of said dogs 109 with said bottom thread mold 41, the molded pipe section, with the thread molds 41 and 51, is raised until clear of said outer mold 4.

During this upward movement of the core, the water valve 97 is held open by its associated mechanism, so that jets of water issue from the holes 100 in the central tube 25, and wash the outer mold 4 as said tube moves upward therethrough.

As a final step in the operation, the. grip per device, carrying the molded pipe sect-ion upon the dogs 109, is lifted off the end of Now both threadmolds,

the central tube 25 by any convenient means attached to the hook 106, and carried to a suitable place of deposit. The gripper device may then be returned to the end of the tube 25, or a new one may be substituted, and the machine is ready for a second cycle of operations, identical in every respect with that described. New thread molds must,'of course, be provided, since those upon the molded pipe section cannot be removed therefrom for twenty-four hours.

In this operation, because the material to be molded is poured into the mold space before the top thread mold is set to place, and because said thread mold closes the mold space by its top flange 51 and because the pressure imposed upon the fluidic mass is sufficient to fill the mold space up to the said top flange, it is evident that by making both end thread molds of precisely similar functional length the result will be that the ends of the molded pipe section will be exactly alike and when fitted together will give perfect abutting joints. I

I claim 1. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed about a mold-containing space; an outer mold in said space, composed of independent sections each provided On its back with a vertical series of spaced thrust plates lying between and guided by opposing faces of adjacent frame members; a reciprocative follower guided by the frame members and bearing against all the thrust plates of its corresponding mold-section, to move the latter inwardly; means connecting the followers with the thrust plates to retract the mold-sections; and an inner mold spaced from the outer mold.

2. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed in the circumference of a circular mold-containing space; an outer cylindrical mold within said space, composed of independent arcuate sections each provided on its back with a vertical series of spaced thrust-plates lying between and guided by opposing faces of adjacent frame members; the sides of said sections between said thrust plates being bent backward and fitted with a cross plate; a reciprocatit e follower guided by the frame members and bearing against all the thrust plates and the cross-plates of its corresponding mold section, to move the latter inwardly; means connecting the followers with the thrust plates to retract the mold-sections; an inner cylindrical mold concentric with and spaced from the outer mold; and annular end thread-molds associated with the outer and inner molds.

' 3. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed about a mold-containing space; an outer mold in said space, composed of independent sections each lying between and guided by opposing faces of adjacent frame members; means for moving said sections in and out to impose pressure upon the material to be molded and to relieve the molded product; an inner mold spaced from the outer mold and composed of independent sections adapted for movement toward and from the outer mold; and means for moving said sections outwardly to initially adjust the inner mold and inwardly to relieve the molded product.

4. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed in the circumference of a circular mold-containing space; an outer cylindrical mold within said space, composed of independent arcuate sections each lying between and guided by opposin faces of adjacent frame members; means for moving said sections in and out to impose pressure upon the material to be molded and to relieve the molded product; an inner cylindrical mold concentric with and spaced from the outer mold and composed of independent arcuate sections adapted for movement toward and from the outer mold; means for moving said sections outwardly to initially adjust the inner mold and inwardly to relieve the molded product; and annular end thread-molds associated with the outer and inner molds.

5. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed about a mold-containin space; an outer mold within said space an compose of independent sections of screen material each lying between and guided by opposing faces of adjacent frame members; an inner mold composed of independent movable sections of screen material; means for moving the sections of the outer mold inwardly to compress the material to be molded to exelude its surplus water content through both screen molds and for moving them outwardly to relieve the molded product; and means for moving the sections of the inner mold outwardly for initial adjustment and inwardly to relieve the molded product.

6. A concrete-pipe machine comprising a frame composed of vertical angle members having their exterior angles symmetrically disposed in the circumference of a circular mold-containing space; an outer cylindrical mold composed of independent arcuate sections of screen material each lying between and guided by opposing faces of adjacent frame members; an inner cylindrical mold composed of independent movable arcuate sections of screen material; means for moving the sections of the outer mold inwardly to compress the material to be molded and to exclude its surplus water content through both screen molds, and for moving them outwardly to relieve the molded product; means for moving the sections of the inner mold outwardly for initial adjustment and inwardly to relieve the molded product; and annular end thread-molds associated with said inner and outer molds.

.7. A concrete-pipe machine comprising associated inner and outer molds; means for adjusting said molds and relieving them from the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a gripper associated with and accompany: ing the shaft to engage the lower end 0 the molded pipe section and lift it from the outer mold; and means for disassociating the gripper with its pipe section load, from the shaft.

8. A concrete-pipe machine comprising associated inner and outer sectional screen molds; means for moving the sections of said molds to expand and contract them; closed end molds associated with the sec tional molds; means for releasing said end molds from their association; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; avgripper associated with and accompanying the shaft to engage the lower end of the molded pipe section and lift it from the outer mold; and means for dis- & associating the gripper with its pipe section load, from the shaft.

9. A concrete-pipe machine comprising associated inner, outer and end molds; means for locking and releasing the end molds inmid from said association; means for adjusting the inner and outer molds, and relieving them from the molded pipe sec tion; a longitudinallymovable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a gripper associated with andaccompanying' the shaft to engage the lower end mold of the molded pipe section and to lift said section with its end molds from the outer mold; and means for disassociating the gripper with its pipe section load, from the shaft.

10. A concrete-pipe machine comprising associated inner and outer molds; means for adjusting said molds, and relieving them from the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a gripper associated with and accompanying the shaft to engage the lower end of the molded pipe section and lift it from the outer mold; means associated with and accompanying the gripper and dependent on its movement for operating it; and means for dis-associating the gripper with its pipe section load, from the shaft. Y

11. A concrete-pipe machine comprising associated inner, outer and end molds; means for locking and releasing the end molds in and from said association; means for adjusting the inner and outer molds, and relieving them from the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft 'and inner mold through the molded pipe section and lifting them again to place; a gripper associated with and accompanying the shaft to engage the lower end mold of the molded pipe section and to'lift said section with its end molds from the outer mold; means associated with and accompanying the gripper for operating it; and means for dis-associating the gripper with its pipe section load, from the shaft.

12. A concrete-pipe machine comprising associated inner and outer molds; means for adjusting them and relieving their cdntaot with the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded'pipe section and lifting. them again to place; a gripper associated with and accompanying the shaft to engage the lower end of the molded pipe section and lift it from the outer mold; means for dis-associating the gripper with its pipe-section load, from the shaft; means operated by the moving shaft for spraying water upon the outer surface of the inner mold as said mold moves down; and means operated by and associated with the moving shaft for spraying Water upon the inner surface of the outer mold as said shaft moves up.

13. A concrete-pipe machine comprising associated inner and outer sectional screen molds and closed end molds; means for locking and releasing the end molds in and from said association; means for moving the sections of the inner and outer molds to expand and contract them; a longitudinally movable shaft in the axis of. and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a gripper associated with and accompanying the shaft to engage the lower end mold of the molded pipe section and to lift said sec,-

tion with its end molds from the outer mold; means associated with and accompanying the gripper for operating it; means for disassociating the gripper with its pipe section'load, from the shaft; means operated by the moving shaft for spraying water upon the outer surface of the inner mold as said mold moves down; and means operated by and associated with the moving shaft for spraying Water upon the inner surface of the outer mold as said shaft moves up.v

14:.- A concrete-pipe machine comprising associated inner and outer molds; means for adjusting said molds and for relieving-them from contact with the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; and a plunger member associated with the moving shaft for spreading upon the inner surface ofthe molded pipe section as it moves down therethrough a coating of cement from a body thereof placed and carried on top of the inner mold.

15 A concrete-pipe machine comprising associated inner and outer'molds; means for adjusting said molds and for relieving them from contact with the molded pipe section; a longitudinally movable shaft in the axis of and carrying said inner mold; means for lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a plunger member associated with the moving shaft for spreading upon the inner surface of the molded pipe section as it moves down therethrough a coating of cement from a body thereof placed and carried on top of the inner mold; a gripper associated with and. accompanying the shaft to engage the lower end of the molded pipe section and lift it from the outer mold; and

means for disassociating the gripper with its pipe section load, from the shaft;

16. A concrete-pipe machine comprising associated inner and outer molds; means for adjusting said molds and for relieving'them from contact with the molde'dpipe section;

a longitudinally movable shaft in the axis of and carrying said inner mold; meansfor lowering said shaft and inner mold through the molded pipe section and lifting them again to place; a plunger member associated with the moving shaft for spreading upon the inner surface of the molded pipe section as it moves down therethrough a coating of cement from a body thereof placedand carried on top of the inner mold; a gripper associated with and accompanying the shaft to engage the lower end of the molded pipe sectionand lift it from the outer mold; means for disassociating the gripper with its pipe-section load, from the shaft; means operated by the moving shaft for spraying water upon the outer surface of the inner mold as said mold moves down; and means operated by and associated with the moving shaft for spraying water upon the inner surface of the outer mold as said shaft moves up.

JULIUS G. ZWICKER.

Witnesses:

WM. F. Boom, D.- B. RICHARDS. 

